Geosteering is known as the process of adjusting the deviation of a wellbore to steer a downhole tool in a desired direction or toward a predetermined target location within an underground reservoir formation. This process generally requires petrophysicists to analyze real-time measurements of various downhole tools so that geological information surrounding the wellbore can be understood and thereby optimized wellbore development can be achieved in real-time. Geosteering inversion based on numerical optimization techniques (e.g., Gauss-Newton gradient inversion) also may be utilized to invert formation geology and minimize any discrepancy between a downhole tool's measurements and forward modeling responses based on the inversion. Such inversion techniques may provide petrophysicists with a way to quickly estimate formation properties in real-time. However, conventional inversion techniques may produce unreliable estimates when, for example, the downhole tool's measurements are not sufficiently sensitive to the targeted formation or the varying formation properties between different formation layers are difficult to distinguish. Without reliable estimates of formation properties, the inversion might fail to produce an effective formation model that minimizes discrepancy between the modeled formation properties and the observed real-world properties of the actual formation.